Best time to buy and sell stock iii

Array Dynamic Programming

53.2% acceptance

Jan 12, 2026

10534

225

You are given an array prices where prices[i] is the price of a given stock on the ith day. Find the maximum profit you can achieve. You may complete at most two transactions. Note: You may not engage in multiple transactions simultaneously (i.e., you must sell the stock before you buy again).

Solution

Rust

Time O(2^n)

Space O(n)

LeetCode

solution.rs

impl Solution {
  pub fn max_profit_iii(prices: Vec<i32>) -> i32 {
    Self::max_profit(prices)
  }
  
  fn max_profit(prices: Vec<i32>) -> i32 {
    let mut buy1 = i32::MIN;
    let mut sell1 = 0;
    let mut buy2 = i32::MIN;
    let mut sell2 = 0;
    
    for price in prices {
      buy1 = buy1.max(-price);
      sell1 = sell1.max(buy1 + price);
      buy2 = buy2.max(sell1 - price);
      sell2 = sell2.max(buy2 + price);
    }
    
    sell2
  }
}